Continuous rod making machines

ABSTRACT

A CONTINUOUS ROD MAKING MACHINE, ESPECIALLY FOR MAKING CIGARETTE FILTER RODS, WAS A HEAT EXCHANGER AFTER THE HEATER TO COOL THE ADHESIVE. THE HEAT EXCHANGER USES AIR AS A COOLING MEDIUM AND ALSO TO FORM AN AIR BEARING. THERE IS ALSO AN AIR BEARING BETWEEN THE GARNITURE BED AND TAPE.   D R A W I N G

1973 E. G. PRESTON CONTINUOUS ROD MAKING MACHINES 2 Sheets-Sheet 1 Filed April 7, 1970 EDWARD GEORGE PRESTON Attorneys Feb. 3, 1973 E. G. PRESTON 3,716,443

CONTINUOUS ROD MAKING MACHINES F1106 April. '7, 1.970 2 Sheets-Sheet 2 EDWARD GEORGE PRESTON Inventor ggwy, 5222/72/0 mafia f Smzfl United States Patent US. Cl. 156-441 16 Claims ABSTRACT OF THE DISCLOSURE A continuous rod making machine, especially for mak ing cigarette filter rods, has a heat exhanger after the heater to cool the adhesive. The heat exchanger uses air as a cooling medium and also to form an air bearing. There is also an air bearing between the garniture bed and tape.

The present invention relates to continuous rod making machines.

In a continuous rod making machine for making cigarette filters, filter material, for example in the form of a web or tow, is fed together with a wrapper along a garniture bed where the wrapper is folded around the filter material to form a rod. After the rod has been substantially formed it is passed through a first folder to fold over a first edge of the wrapper and then through a second folder to fold over the second edge of the wrapper. The second folder may also incorporate a diameter control by which the diameter of the rod can be varied. In the case where heat-sensitive adhesive is applied to the second edge of the wrapper, prior to its introduction onto the garniture bed, a heater is incorporated in the second folder to heat the adhesive prior to the folding over of the second edge over the already folded first edge. It has been found that with the increasing speed used in such continuous rod making machines the heat generated by the frictional forces resulting from the rapid movement of the rod through the garniture bed and folder has given rise to unsatisfactory sticking down of the second edge of the wrapper in that there is a tendency for the two edges to creep an undesirable amount with respect to one another after the rod has left the second folder. Some creep will however occur in any event, but when a relatively springy or resilient filler is used in the rod then the adhesive may be unable to hold the two edges of the wrapper together against the resilience of the filler, after the rod has left the confines of the second folder and before the adhesive can set, with the result that the rod bursts along the seam.

According to one aspect of the present invention a continuous rod making machine includes a garniture tape movable over a garniture bed to carry a wrapper and a filler; a folding arrangement positioned above the garniture bed to fold the wrapper around the filler; a heater to heat a heat-sensitive adhesive carried by the wrapper; and a heat exchanger positioned immediately downstream of the folding arrangement to cool the heat sensitive adhesive as it leaves the folding arrangement.

According to this aspect of the invention a method of forming a continuous rod comprises feeding a wrapper tape onto a garniture tape moving along a garniture bed; feeding a filler onto the wrapper tape carried by the garniture bed; forming the wrapper and filler into a continuous rod; folding over a first edge of the wrapper over the filler; folding a second edge of the wrapper over the first edge and applying heat to activate a heatsensitive adhesive between the two edges to stick the edges together; and cooling the continuous rod after the heat has been applied.

According to another aspect of this invention, in a contnuous rod making machine including a garniture tape moving along a garniture bed, air is blown through the garniture bed, below the tape, to form a film of air between the tape and the bed. This aspect of the invention in particular applies to cigarette making ma.- chines, as well as to cigarette filter rod making machines.

The garniture tape usually carries the wrapper tape all the way until the rod has been completely formed, with the edges of the wrapper secured together by an adhesive. In principle, however, when using an air bearing according to the present invention, it may be possible to support the wrapper directly with the aid of an air bearing acting between the wrapper itself and the garniture bed (or another stationary member) for at least part of the movement of the wrapper before the edges are joined to form a complete rod.

According to another aspect of the present invention a heat exchanger, especially for use in a continuous rod making machine, comprises a body portion having at least one passage in it into which fluid can be introduced and from which the fluid can be ejected to an external surface of the body portion so that the ejected fluid can cool an article placed adjacent the said surface and also form a fluid bearing between the body portion and the said article.

How the invention may be carried out will now be described with reference to the accompanying drawings in which:

FIG. 1 is a side elevational, part sectional view of a continuous rod making machine incorporating the present invention;

FIG. 2 is a section through the heat exchanger section;

FIG. 3 is a cross-section taken on the line AA of FIG. 2; and

FIG. 4 is a section through the garniture on the line IV--IV in FIG. 1.

The continuous rod making machine shown is one for use in making filter plugs and comprises essentially a garniture bed 1 over which a continuous garniture tape 2 passes, a folding arrangement 3 being positioned above the garniture bed 1 to fold the wrapper around the filter material.

A tongue assembly 4 is positioned upsteam of the folding arrangement 3 to compress the filter material to form the rod. The details concerning the construction of the tongue assembly 4 are disclosed in copending US. application Ser. No. 26,315 filed Apr. 7, 1970 to Horace Alexander Stone.

The garniture tape 2 passes around the rollers 6, 7 and 8, the roller 6 being mounted on a swinging arm so that the portion 2a of the garniture tape 2 can be moved a limited amount in a plane substantially normal to the plane of the drawing to centralize the garniture tape on the garniture bed 1.

The wrapper tape 9 passes around a roller 10 from a spool (not shown) via an adhesive applying station (not shown) by which adhesive is applied along one edge of the wrapper. The adhesive is heat-sensitive polyvinyl acetate (P.V.A.).

The folding arrangement comprises a first folder 11 which folds over a first edge of the Wrapper 9, and downstream of the first folder 11 is a second folder 12 which folds down the second glued edge of the wrapper 9 and incorporates a heater to heat the P.V.A. adhesive on the wrapper. A diameter control 13 is automatically adjustable in a vertical direction by a servo-motor 14 in response to signals indicative of rod diameter from a sensor 15 to correct trends in variations of the rod diameter.

The heat exchanger 17 is positioned immediately downstream of the heater to cool the -P.V.A. and set it before the resilience of the filler can act to burst open the wrapper as the rod leaves the confines of the folder 12. The heat exchanger 17 comprises a body portion 18 having a main passage 19 in it into which fluid, in this case air, can be introduced. A plurality of cooling passages 20 are in communication with the main passage 19 and with an external surface 21 of the body portion 18.

The external surface 21 is an arcuate shape, as seen in FIG. 3, to conform substantially with the shape of the continuous filter rod which emerges from the folder 12. The heat exchanger 17 is mounted on an arm which itself is pivotally mounted on the machine so that the weight of the heat exchanger 17 causes it to tend to rest on the continuous rod.

The open end of the main passage 19 is connected by a pipe 19A to the compressed air supply (not shown) by which air under pressure can be supplied through the main passage 19 and thence to the cooling passages 20. Pressurized air emerging from the passages 20 against the surface of the continuous rod passing beneath the heat exchanger 17 will cause the body portion 18 to be raised off the surface of the continuous rod by the formation of an air bearing between the body portion 18 and the surface of the continuous rod. The main passage 19 is preferably tapered towards its blind end so that the pressure of air emitted by the passages 20 is substantially equal along the length of the main passage 19.

Thus, air emitted through the cooling passages 20 both serves to keep the body portion 18 clear of the continuous rod and also to cool the adhesive on the wrapper of the continuous rod and thus inhibit excess creeping of the two edges of the wrapper with respect to one another.

FIG. 4 is a section through the line IV-IV in FIG. 1. It shows that air is blown upwards through holes 22 in the garniture bed 1 from a manifold 23. This air during use forms a thin film of air serving as an air bearing between the garniture bed 1 and the garniture tape 2, thus preventing an excessive rise of temperature due to friction in the garniture.

As an example the garniture tape may support the wrapper '(in either a cigarette making machine or a cigarette filter rod making machine) along a total distance of approximately 84 centimetres. The air holes extend up wards through the garniture bed at intervals mainly of 2 centimetres and are of 0.8 millimetre diameter, the air pressure in the manifold 23 being approximately 15 pounds per square inch. The pitch between holes is reduced to provide more air in regions of high pressure on the garniture tape, notably under the tongue where it compresses the filler down to its final cross-section; in such high-pressure regions the holes may be at intervals of '1 centimetre over a distance of say about 6 centimetres. The pitch of the holes may for example also be reduced in the region beneath the folder 3.

What I claimas my invention and desire to secure by Letters Patent is:

1. A cigarette filter making machine comprising an endless garniture tape supported for movement along a path by a garniture bed, said garniture tape being adapted to support the elements of a cigarette filter during formation into a continuous rod, means for feeding a continuous paper wrapper web onto said garniture tape; means for feeding a tow of filter material onto the wrapper web on the garniture tape; means for compressing the filter material by applying pressure on the filter material towards the garniture tape and bed; means for folding the continuous wrapper web around the compressed filter material while the filter material is being supported by the garniture tape; means for applying a heat-settable adhesive along a first edge of the wrapper web; means for pressing the said first edge of the wrapper web against the second edge of the wrapper web to form a continuous rod; means for applying heat to the edges of the paper wrapper web while the first edge is being pressed against the second edge to cause the adhesive to set; and means immediately downstream of said heating means for applying pressure to the adhesive joint and simultaneously cooling the adhesive to secure the adhesive joint between the edges of the paper wrapper web against any significant creeping open under the influence of the bursting pressure applied to the wrapper web by the compressed filter material, said tow feeding means, tow compressing means, wrapper web folding means, adhesive applying means, pressing means, heat applying means, and pressure and cooling means being arranged along said path adjacent said garniture tape.

2. A cigarette filter making machine according to claim 1 wherein said means for applying a heat-scalable adhesive is adapted to apply polyvinyl acetate.

3. A cigarette filter making machine according to claim 1 wherein said pressure and cooling means comprises a fluid delivery means and a body portion including means defining a passage through which fluid is delivered by the fluid delivery means to an external surface of the body portion which lies adjacent to the adhesive joint, whereby the fluid cools the adhesive joint and also forms a fluid bearing between the body portion and the wrapper web.

4. A continuous rod making machine including garniture means for enclosing a filler stream in a continuous wrapper web, said garniture means comprising (a) a garniture bed,

(b) a garniture tape for supporting said continuous wrapper web and filler stream,

(c) means for feeding said garniture tape along said garniture bed, and

(d) means for forming and maintaining a film of fluid between said garniture tape and said garniture bed as said garniture tape moves along said garniture bed,

(e) whereby friction between said garniture bed and garniture tape is prevented and excessive rise in temperature of said continuous wrapper and filler is avoided.

5. A continuous rod making machine according to claim 4 wherein said garniture bed is perforated and said means for maintaining a fluid film between said garniture tape and garniture bed comprises means for projecting streams of fluid through said perforations in said garniture bed to form said fluid film.

6. A continuous rod making machine according to claim 5 wherein the holes in the garniture bed are arranged closer together in regions where greater pressure is applied to the garniture tape than at other regions where less pressure is applied to the garniture tape.

7. In a continuous rod making machine comprising (a) a garniture bed,

(b) an endless garniture tape for supporting a continuous paper wrapper web having a filler stream on said wrapper web,

(c) means for feeding said garniture tape while supporting said continuous wrapper web and filler stream along a path defined by said garniture bed while said wrapper web and filler stream are formed into a continuous rod,

(d) means for applying a heat-scalable adhesive along one longitudinal edge of the wrapper web, and

(e) means for tightly folding the continuous paper wrapper web about the filler stream with the one longitudinal edge overlapping the other longitudinal edge and for pressing and heating said overlapping edges to form an adhesive joint while said rod is supported on said garniture tape;

(f) the improvement comprising means for preventing an excessive rise in temperature of said continuous paper wrapper web and filler stream,

(g) said means for preventing an excessive temperature rise comprising means for forming and maintaining a film of fluid between said garniture tape and said garniture bed to prevent an excessive rise in temperature of said continuous paper wrapper web and filler stream caused by friction between said garniture bed and garniture tape, and means along said path immediately downstream of said folding, pressing and heating means for applying pressure to the adhesive joint and simultaneously cooling and setting the adhesive between said overlapping edges While the continuous rod is supported on said garniture tape,

(h) said adhesive applying means; folding, pressure and heating means, and cooling means being arranged along said path adjacent said garniture'tape,

(i) whereby creeping of the adhesive joint caused by the pressure of the filler material against the interior surface of the folded paper wrapper web is avoided.

8. A continuous rod making machine as defined in claim 7 further comprising means for compressing said filler stream on said continuous wrapper web.

9. A continuous rod making machine according to claim 7 wherein said pressure and cooling means comprises means for directing a fluid stream against the surface of said wrapper web to cool the adhesive joint.

10. A continuous rod making machine according to claim 9 wherein said pressure and cooling means comprises a body portion having a main passage connected to a source of fluid and a plurality of cooling passages connected to said main passage for conducting a plurality of said fluid streams against the external surface of the wrapper Web at said adhesive joint.

11. A continuous rod making machine according to claim 10 wherein the surface of said body portion ad jacent said adhesive joint has a configuration substantially conforming to the external configuration of at least a part of the surface of the folded wrapper web, said cooling passages terminating at said conforming surface.

12. A continuous rod making machine according to claim 11 wherein said conforming surface is arcuate in shape.

13. A continuous rod making machine according to claim 11 wherein said body portion is arranged above said folded wrapper web to be urged towards the adhesive joint by gravity such that said conforming surface rests on the wrapper web surface, the fluid from said plurality of cooling passages forming a fluid bearing between the conforming surface of the body portion and the surface of the wrapper Web.

14. A continuous rod making machine according to claim 10 wherein said main passage extends substantially parallel to said folded continuous Wrapper web, and said cooling passages extend transversely from said main passage at spaced intervals along the length thereof, the cross-section of said main passage being tapered between the end connected to said fluid source and the opposite end thereof whereby the pressure of the fluid emitted by the cooling passages will be substantially equal.

15. A continuous rod making machine according to claim 7 for producing a cigarette rod.

16. A continuous rod making machine according to claim 7 for producing a cigarette filter rod.

References Cited UNITED STATES PATENTS 1,810,944 6/1931 Bronander 156-498 3,560,298 2/1971 McArthur et a1. 156-180 X 3,016,945 1/1962 Wexler 156-441 X 1,827,138 10/1931 Brancart 226-97 X 1,838,142 12/1931 Harrington 226-97 X 3,095,343 6/1963 Berger 156-441 X BENJAMIN A. BORCHELT, Primary Examiner G. E. MONTONE, Assistant Examiner US. Cl. X.R. 

